Reanimation: Catalytically inactive π‐allyl ironcomplexes are “reanimated” upon addition of N‐heterocyclic carbene ligands such as 1,3‐dimesitylimidazolin‐2‐ylidene (SIMES). A comparison of stoichiometric and catalytic allylic alkylation reactions shows the π‐allyl mechanism to be active in this catalytic system.
Manganese(III)-Mediated Transformations of Phloroglucinols: A Formal Oxidative [4 + 2] Cycloaddition Leading to Bicyclo[2.2.2]octadiones
作者:Branko Mitasev、John A. Porco
DOI:10.1021/ol900590t
日期:2009.6.4
Manganese(III)-mediated oxidativetransformations of dearomatized phloroglucinol (1,3,5-trihydroxybenzene) derivatives are reported. A number of cyclization modes have been observed, including polycyclization to afford bicyclo[2.2.2]octadiones via a formal oxidative radical [4 + 2] cycloaddition.
The biomimetic synthesis of fused bispyran via Lewis acid mediated tandem oxacyclization of a 1,4,7-polyepoxide is explored. The nature of the Lewis acid promoter is critical for the endo-regioselectivity of epoxide cyclization, although anomalous apparent retention of stereochemistry is observed at some reactive centers.
New phenols are described containing an alkyl substituent containing a functional group; as well as a process for the production of such phenols. The new phenols are useful e.g. as stabilizers in organic or aqueous systems.